A sack-hauling time traveler from the 21st century lands in an Irish potato field in 1849, just before a terrible famine, and asks: If you thought genetically modified (GM) potatoes could avert late blight disease, spare a million countrymen from starvation and keep another million from emigrating off the Emerald Isle, would you plant these newfangled spuds?

Fast forward to the Internet Age, when communication researchers ran 859 U.S. grocery shoppers through a similar thought experiment: Half the subjects in an online survey read the story of the 1850s Irish Potato Famine, learning the potential impact of fungal Phytophthora infestans on potato and tomato crops today. The other 400-plus pondered generic plant disease, with no mention of specific crops or historic famines.

QUIZ: Fried green catfish tomatoes

Test your knowledge of agricultural genetic engineering with this true/false quiz, from the “Factors influencing U.S. consumer support…” study:

1. Genetically modified tomatoes contain genes while ordinary tomatoes do not.
2. Genetically modified animals are always bigger than ordinary animals.
3. Tomatoes genetically modified with genes from catfish would probably taste fishy.
4. By eating a genetically modified fruit, a person's genes could also become modified.

* See answers below.

“Stories of the Irish Potato Famine were no more likely to boost support for disease-resistant GM crops than were our generic crop-disease descriptions,” says Cornell’s Katherine A. McComas.

“Preconceived views about risks and benefits of agricultural genetic engineering – and perceptions about the fairness and legitimacy of the decision-making process – these things matter most,” says McComas, professor and chair of the Department of Communication in the College of Agriculture and Life Sciences (CALS).

With co-authors John C. Besley (Michigan State University) and Joseph Steinhardt (CALS), McComas will publish study results as “Factors influencing U.S. consumer support for genetic modification to prevent crop disease” in the July 2014 journal Appetite – right about the time airborne P. infestansspores are drifting through home-garden tomato crops.

“If you think GM crops are dangerous ‘frankenfoods’ and/or that crop disease is best controlled with chemicals – if you suspect federal regulators care more about Big Ag’s interests than your family’s, thus the whole game is rigged – plaintive tales of historical famines won’t change your mind about GM for disease resistance,” McComas said.

In fact, Americans tend to support GM and see more benefits than risks (although some concerns over safety and morality persist), the researchers noted as their survey began. Another fact is that no commercially available GM plant varieties are truly resistant to late blight (although genetic engineers are hard at work).

To assess the GM IQ of their online study participants, researchers began with a true/false quiz (see sidebar). Then they asked participants to self-assess, for example, with this kind of statement: “I understand how biotechnology (genetic engineering, genetic modification) works.”

Since the fairness and legitimacy of the decision-making process among federal government agencies is a matter of opinion, survey participants had their way with statements like “Decision-makers try hard to understand the views of people like me” and “Decision-makers have a right to increase the use of biotechnology in agriculture.”

Sorting through results, the researchers found more hybridized perception/opinions than tomato varieties in a seed catalog, but they reached a couple conclusions:

“While support [for disease-resistant GM crops] may be a function of views about risks and benefits, legitimacy perceptions come from views about decision-making processes,” they wrote.

Also, while dreadful famines make good stories, long-gone Irish folk can’t change minds already made up.

* ANSWERS: Nos. 1, 2 and 4 are clearly false. No. 3 probably isn’t happening – yet.